Compact Figure8 Collider Ring Lattice Alex Bogacz Compact

Compact Figure-8 Collider Ring Lattice Alex Bogacz Compact Collider lattice (Ion Ring) ring at 60 Ge. V no need for strong focusing 600 phase adv/cell FODO lattice minimum dispersion lattice (periodic) no geometric disp. suppression at arc ends Chromatic compensation with sextupoles – large IR chromaticity CASA Meeting, Alex Bogacz October, 5, 2009

Compact Figure-8 Collider Ring 60 deg total ring circumference: 660 m CASA Meeting, Alex Bogacz October, 5, 2009

Proposed (weakly focusing) Ion Ring – lattice (60 Ge. V) phase adv/cell (Dfx= 600, Dfy=600) Arc dipoles $Lb=180 cm $B=64. 7 k. G Arc quadrupoles $Lb=40 cm $G= 10. 1 k. G/cm CASA Meeting, Alex Bogacz October, 5, 2009

Minimum disp. Ion Ring – lattice (60 Ge. V) phase adv/cell (Dfx= 600, Dfy=600) 18 cells (2400 bend) Arc dipoles $Lb=180 cm $B=64. 7 k. G CASA Meeting, Alex Bogacz Arc quadrupoles $Lb=40 cm $G= 10. 1 k. G/cm October, 5, 2009

IR - Natural Chromaticity b* f l* IP FF with focal length f CASA Meeting, Alex Bogacz October, 5, 2009

Chromatic compensation with sextupoles – 600 lattice phase adv/cell (Dfxy= 600) Uniform pattern for 3 families of orthogonal sextupoles – cancellation of spherical aberrations Dfxy= 1800 CASA Meeting, Alex Bogacz October, 5, 2009

Conclusions Ion ring does not require a strong focusing lattice (120 deg. ) 60 deg. FODO is sufficient Quad strength lowered to 100 Tesla/m Small dispersion in the arc recovered through geometric disp. suppression with ‘missing dipoles’ One can have both: reasonable quad strength and small dispersion Complete design of Figure-8 ring Adjusted bend to close 240 deg. lobs (6. 7 Tesla 1. 8 m dipoles) Ring layout (660 meter circumference) Chromatic compensation with sextupoles – large chromaticity of the IRs 600 lattice - Uniform pattern for 3 families of orthogonal sextupoles – cancellation of spherical aberrations, modest sextupole strength required CASA Meeting, Alex Bogacz October, 5, 2009